A site I find usefull on (Belgian) medication is:
Belgisch Centrum voor Farmacotherapeutische Informatie (B.C.F.I. vzw)
using google I find biodramina's active ingredient is diphenhydramine (
http://goldpharma.com/?show=search&search_srt=BIODRAMINA〈=ENGLISH). When I search the bcfi-site for this ingredient I find this:
Gecommentarieerd Geneesmiddelenrepertorium . So medicines for sale in Belgium containing this ingredient can be found in several groups: in lotions and cream for external use, for use in allergic conditions (hay fever, allergic sinusitis etc) with mention of the use as anti-emetic (= anti vomit) and agains motion sickness (so this explains its use against sea sickness), and as an (old) anxiolytic, sedative and hypnotic medicine.
The last indication (same dose as the anti-allergic one: 50 mg) sounds rather worrying when planning to dive...